DARTMOUTH -- So what if the Chinese invented fade-proof inks 4,600 years ago? Nathan Tardif, working in the basement of his modest seaside home here, thinks he can do it better.
Hence the bold challenge laid down on the website of his 18-month-old company, Noodler's Ink LLC, addressed to the ''forgers and identity thieves": He'll pay $1,000 to anyone who can remove his Noodler's Black from a standard security check.
''Industrial bleach will rot the pulp of the paper before it removes the ink," he said. ''As to forgers who are using ultraviolet light to fade out signatures, my ink is also impervious to that."
Tardif, 31, spent the formative years of his adolescence buying antique fountain pens and learning lost repair arts, such as retipping gold nibs with iridium, the smooth metal that actually touches the paper. He turned his attention to ink after a pen lover issued a challenge of his own. ''He said, 'Give me a fountain pen ink that I can use on the newspaper crossword puzzle but won't bleed into the paper and won't show through on the other side, and I'll buy 18 bottles,' " Tardif recalled.
He went far beyond that initial goal. His line of inks span a rainbow of vibrant colors. His naming runs to the poetic and obscure. A bloody red is called Antietam, after the Civil War battle; a dark teal is called Squetegue, inspired by the skin of what is commonly known as weakfish.
Amid a plethora of established brands from the big pen companies, Noodler's is catching on among fountain pen users.
''A lot of people are asking for it by name," said Bruce Poduska, sales manager at Bromfield Pen Shop in Boston. ''The colors are just really, really rich, and it seems to fit a niche. Fountain pen people are pretty picky. They're looking for just the right shade of hot pink, not too pink and not too hot."
Recently Tardif prepared a weekly shipment of eight cases, 144 bottles each. Noodler's typically retails for $12 a bottle, and he confided that profits per bottle ''stink."
''I'm hanging on by the skin of my teeth," he said.
Still he perseveres, with a crotchety stubbornness that would make Andy Rooney proud. Among his latest concoctions is Firefly, an intense chartreuse that outblazes the typical highlighter pen.
''It looks like it's from Mars," Tardif said. ''People just hold up the bottle, and it sells itself."
Planning an Arctic expedition? Try Noodler's Polar Black, guaranteed to flow at temperatures down to -110 degrees Fahrenheit. ''It sells OK in Scandinavia and Canada," Tardif said.
Still in the works are Bumblebee, which will produce a line of alternating black and yellow stripes; Christmas ink, which will change color from red to green as the temperature rises; and glow-in-the-dark ink.
Underpinning the venture is an old-fashioned, made-in-America pride. Tardif said he was dismayed when he learned that several US pen makers were manufacturing their ink overseas. ''I thought that Americans were more than capable of making a better ink and making it competitively, even in Massachusetts," he said.
Jeffrey Krasner can be reached at email@example.com.